(4) "Message" means a communication conveyed by means of a visual display of text.

(5) "Sign assembly" means the display, border, trim and all supporting apparatus, including posts, columns, pedestals and foundation.

(6) "Time and temperature sign" means a changeable sign that electronically or mechanically displays the time and temperature by the complete substitution or replacement of a display showing the time with a display showing the temperature.

B. The display on each side of a changeable sign:

(1) May be changed no more than once every 20 minutes, unless the municipality in which the sign is located adopts an ordinance to the contrary and notifies the Department of Transportation in writing of that ordinance;

(2) Must change as rapidly as technologically practicable, with no phasing, rolling, scrolling, flashing or blending, unless the municipality in which the sign is located adopts an ordinance to the contrary and notifies the Department of Transportation in writing of that ordinance.__Notwithstanding this subparagraph, a municipality may not adopt an ordinance that allows the sign to flash; and

(3) May consist only of alphabetic or numeric text on a plain background and may not include any graphic, pictorial or photographic images.

C. The display may comprise no more than 50% of the surface area of a changeable sign.

D. No more than one changeable sign with 2 sides is allowed per lot of record.

E. Changeable signs may not be located so that the message is readable from a controlled-access highway or ramp.